Skocz do pozycji: 1.

Tytuł:

Wpływ warunków środowiskowych na starzenie magnesów trwałych Nd-Fe-B
Application properties of permanent magnets Nd-Fe-B

Autorzy:

Drak, M.
Dobrzański, L.A.

Powiązania:

https://bibliotekanauki.pl/articles/1374783.pdf

Data publikacji:

2006

Wydawca:

Sieć Badawcza Łukasiewicz - Instytut Napędów i Maszyn Elektrycznych Komel

Tematy:

magnes trwały
starzenie
odporność korozyjna

Opis:

The paper presents results of corrosion wear of bonded and sintered hard magnetic materials Nd-Fe-B and magnets covered by protective polymer, lacquer and metal coatings. Corrosion tests were made in the water and in 5% NaCl solution environment. It was found that the bonded magnets with the polymer matrix demonstrate better corrosion resistance than the sintered magnets. Employment of the protective coatings on the Nd-Fe-B bonded magnets surfaces may feature the effective protection of the substrate material from the corrosive action of the aggressive agent. Analysis of the surface topography of the deposited protective coatings makes it possible to determine coating defects resulting from the action of the aggressive agent. The best protection from the corrosive environment is provided by the polymer coatings. Lower corrosion protection by protective coating was found in the case of sintered magnets. The corrosion damage process of magnets covered with the protective coatings starts in the coating failure location and is connected with the further damage proceeding both into the material and on its surface.

Źródło:

Maszyny Elektryczne: zeszyty problemowe; 2006, 74; 135-140
0239-3646
2084-5618

Pojawia się w:

Maszyny Elektryczne: zeszyty problemowe

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 2.

Tytuł:

High-coercivity Nd-Fe-B Powders Obtained by High-Temperature Milling
Wysokokoercyjne proszki Nd-Fe-B otrzymywane przez mielenie w wysokiej temperaturze

Autorzy:

Kaszuwara, W.
Michalski, B.
Orlowski, P.

Powiązania:

https://bibliotekanauki.pl/articles/355400.pdf

Data publikacji:

2014

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

hard magnetic materials
Nd-Fe-B
mechanical alloying
mechanical milling
twarde materiały magnetyczne
mechaniczna synteza
obróbka mechaniczna

Opis:

The possibility of employing high temperature milling (600°C) for the production of highly coercive Nd-Fe-B powders was examined. The materials were the Nd₁₂Fe₈₂B₆, alloy which was subjected to mechanical milling and the powders of the constituent elements of this alloy which were processed by mechanical alloying. The processes were conducted in the two variants: the first variant consisted of mechanical milling performed at a high temperature which was maintained during the entire process, and the other variant included preliminary milling carried out at room temperature and then the milling temperature was increased. All the processes gave nanocrystalline powders with hard magnetic properties. The powders produced by mechanical milling had better properties than those produced by mechanical] alloying as they were more homogeneous and contained smaller amounts of the α-Fe phase.
W pracy badano możliwości zastosowania procesu mielenia w wysokiej temperaturze (600°C) do otrzymywania wyso- kokoercyjnych proszków Nd-Fe-B. Mieleniu poddano stop Nd₁₂Fe₈₂B₆,. a także zastosowano metodę mechanicznej syntezy stopów tzn. mielono proszki pierwiastków składników stopu. Procesy prowadzono w dwóch wariantach: cały proces odbywał się w podwyższonej temperaturze lub stosowano wstępne mielenie w temperaturze pokojowej, a następnie mielenie w wysokiej temperaturze. We wszystkich procesach uzyskano nanokrystalicze proszki o właściwościach magnetycznie twardych Proszki uzyskane w procesie mielenia stopu miały właściwości lepsze od proszków otrzymanych w procesie mechanicznej syntezy stopów, ponieważ były bardziej jednorodne i posiadały mniejszy udział fazy α-Fe.

Źródło:

Archives of Metallurgy and Materials; 2014, 59, 1; 47-50
1733-3490

Pojawia się w:

Archives of Metallurgy and Materials

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 3.

Tytuł:

Microstructure and magnetic properties of Nd-Fe-B-(Re, Ti) alloys

Autorzy:

Hasiak, M.

Powiązania:

https://bibliotekanauki.pl/articles/147728.pdf

Data publikacji:

2015

Wydawca:

Instytut Chemii i Techniki Jądrowej

Opis:

The microstructure and magnetic properties of nanocomposite hard magnetic Nd-Fe-B-(Re, Ti) materials with different Nd and Fe contents are studied. The role of Re and Ti addition in phase composition and volume fraction of the Nd-Fe-B phase is determined. All samples are annealed at the same temperature of 993 K for 10 min. Mössbauer spectroscopy shows that the addition of 4 at.% of Re to the Nd8Fe78B14 alloy leads to creation of an ineligible amount of the magnetically hard Nd2Fe14B phase. Moreover, the microstructure and magnetic characteristics recorded in a wide range of temperatures for the Nd8Fe79–xB13Mx (x = 4; M = Re or Ti) alloys are also analyzed.

Źródło:

Nukleonika; 2015, 60, 1; 29-33
0029-5922
1508-5791

Pojawia się w:

Nukleonika

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 4.

Tytuł:

Multistep Heat-Treatment Effects on Electrospun Nd-Fe-B-O Nanofibers

Autorzy:

Jeon, E. J.
Eom, N. S. A.
Lee, J.
Lee, B.
Cho, H. M.
On, J. S.
Choa, Y.-H
Kim, B. S.

Powiązania:

https://bibliotekanauki.pl/articles/354311.pdf

Data publikacji:

2018

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

Nd-Fe-B
nanofibers
electrospinning
heat treatment

Opis:

Neodymium-Iron-Boron (Nd-Fe-B) magnets are considered to have the highest energy density, and their applications include electric motors, generators, hard disc drives, and MRI. It is well known that a fiber structure with a high aspect ratio and the large specific surface area has the potential to overcome the limitations, such as inhomogeneous structures and the difficulty in alignment of easy axis, associated with such magnets obtained by conventional methods. I n this work, a suitable heat-treatment procedure based on single-step and multistep treatments to synthesize sound electrospun Nd-Fe-B-O nanofibers of Φ572 nm was investigated. The single-step heat-treated (directly heat-treated at 800°C for 2 h in air) samples disintegrated along with the residual organic compounds, whereas the multistep heat-treated (sequential three-step heat-treated including three steps;: dehydration (250°C for 30 min in an inert atmosphere), debinding (650°C for 30 min in air), and calcination (800°C for 1 h in air)) fibers maintained sound fibrous morphology without any organic impurities. They could maintain such fibrous morphologies during the dehydration and debinding steps because of the relatively low internal pressures of water vapor and polymer, respectively. In addition, the NdFeO₃ alloying phase was dominant in the multistep heat-treated fibers due to the removal of barriers to mass transfer in the interparticles.

Źródło:

Archives of Metallurgy and Materials; 2018, 63, 3; 1433-1437
1733-3490

Pojawia się w:

Archives of Metallurgy and Materials

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 5.

Tytuł:

Polymer - Bonded Magnetic Materials with Various Nd-Fe-B Filler Content

Autorzy:

Grujić, A.
Lazić, N.
Talijan, N.
Spasojević, V.
Stajić-Trošić, J.
Ćosović, V.
Aleksić, R.

Powiązania:

https://bibliotekanauki.pl/articles/1538172.pdf

Data publikacji:

2010-05

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

75.50.Ww
81.05.Qk
83.85.Vb
46.35.+z
81.70.Pg
91.60.Pn
68.37.Hk

Opis:

One of the more important developments in magnetic materials, polymer bonded magnets, have opened a new world of application opportunities. The Nd-Fe-B/polymer composite materials offer an excellent combination of strong magnetic and dynamical-mechanical properties. However, the transition temperatures of filler and matrix should be selected carefully considering the future application. Uniform particle distribution and good adhesion between Nd-Fe-B powder particles and polymer are essential for the quality of the composite, while stiffness of polymer matrix is one of the influencing factors as well. The damping properties of Nd-Fe-B/polymer composites with 15 wt.%, 50 wt.% and 75 wt.% of Nd-Fe-B powder were studied by dynamic mechanical analysis and compared with a pure polymer sample. Thermal stability was analyzed using a simultaneous differential scanning calorimetric and thermogravimetric analysis technique.

Źródło:

Acta Physica Polonica A; 2010, 117, 5; 859-863
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 6.

Tytuł:

Structure and Properties of Nd-Fe-B Alloy Subjected to HDDR Process

Autorzy:

Szymański, M.
Michalski, B.
Leonowicz, M.
Miazga, Z.

Powiązania:

https://bibliotekanauki.pl/articles/352047.pdf

Data publikacji:

2016

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

HDDR
magnets hydrogenation
Nd-Fe-B alloy
neodymium magnets
magnets recycling

Opis:

In this paper the Hydrogenation, Disproportionation, Desorption and Recombination (HDDR) route was tested, for the Nd-Fe-B master alloy, as a prospective procedure for recycling of sintered scrap neodymium magnets. The HDDR method is based on the hydrogen induced reversal phase transformation of Nd-Fe-B alloy: Nd₂Fe₁₄B + (2±x) H₂ = 2NdH_2±x + Fe₂B + 12Fe. Microstructural observations (SEM), phase constitution studies (XRD) and measurement of magnetic properties (VSM) were done to investigate the HDDR transformation progress. It was observed that disproportionation reaction starts at the grain boundaries, where the Nd-rich phase is located. Average grain size was reduced and coercive material was produced as a result of the HDDR process. Obtained results are similar to literature data.

Źródło:

Archives of Metallurgy and Materials; 2016, 61, 1; 217-220
1733-3490

Pojawia się w:

Archives of Metallurgy and Materials

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 7.

Tytuł:

57Fe Mössbauer effect study of Nd-Fe-B hybrid bonded magnets

Autorzy:

Płusa, D.
Olszewski, J.
Dośpiał, J.

Powiązania:

https://bibliotekanauki.pl/articles/148344.pdf

Data publikacji:

2007

Wydawca:

Instytut Chemii i Techniki Jądrowej

Tematy:

bonded magnets
Mössbauer effect
coercivity
remanence

Opis:

An investigation of magnetic interaction between the particles of hybrid bonded magnets based on mixtures of Nd-(Fe,Co)-B and strontium ferrite powders was carried out. An enhancement of the magnet remanence and coercivity caused by the interaction between their components was observed. From Mössbauer effect study, it results that this enhancement can be correlated with the increase of an average hyperfine field at Fe sites in Nd-(Fe,Co)-B magnets with the strontium ferrite addition.

Źródło:

Nukleonika; 2007, 52, supl. 1; 89-92
0029-5922
1508-5791

Pojawia się w:

Nukleonika

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 8.

Tytuł:

Consolidation of Nanocrystalline Nd-Fe-B Powder by Hydrostatic Extrusion at High Temperature

Autorzy:

Gizynski, T.
Kaszuwara, W.
Kulczyk, M.
Leonowicz, M.

Powiązania:

https://bibliotekanauki.pl/articles/1030247.pdf

Data publikacji:

2017-05

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

75.50.Ww

Opis:

Hydrostatic extrusion is a modern method of shaping material microstructure and properties. Hydrostatic extrusion can also be successfully used for consolidation of hard magnetic powders. The effect of extrusion temperature, within the range of 700-800°C, on the magnetic properties of the bulk, final product was studied. A commercial MQU-F42 powder, dedicated to hot pressing, was placed in copper capsules and initially cold compacted up to 60% of the theoretical density. Subsequently, the billet was heated in an oven to temperatures 700 and 800°C, respectively and subjected to hydrostatic extrusion. The extruded product had a form of a copper rod, with the Nd-Fe-B core, having 96% of theoretical density (true strain 1.85 after extrusion at 800°C). The extrusion process led to deterioration of the coercivity, for which coarsening of the Nd₂Fe₁₄B grains was blamed. In order to prove this hypothesis, the starting powder was annealed in a temperature range of 550-900°C for various times. The crystallite size, measured after annealing by the X-ray diffraction method, showed that with extension of time and elevation of the temperature the crystallite size increases, however the dominating parameter is the temperature. Correlation of the crystallite size with temperature indicates that when the crystallites are larger than 80 nm the magnetic properties dramatically decrease. Additionally, after HE at 800°C micrometric size Nd-rich phase appear in the microstructure. The Nd is squeezed from the grain boundary of the Nd₂Fe₁₄B phase leading to non-isolated grains, which also contributes to the deterioration of the coercivity.

Źródło:

Acta Physica Polonica A; 2017, 131, 5; 1260-1263
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 9.

Tytuł:

Magnetic Properties of Bulk and Thin Nd₂Fe₁₄B Films after Corrosion Action

Autorzy:

Constantin, V.
Neacşu, E.
Popescu, A.
Galyas, A.
Demidenko, O.
Yanushkevich, K.

Powiązania:

https://bibliotekanauki.pl/articles/1385675.pdf

Data publikacji:

2015-02

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

61.05.cp
75.50.Bb
75.50.Vv
75.70.-i

Opis:

The corrosion action for bulk and thin Nd₂Fe₁₄B films magnets in different corrosion media was studied. The thin Nd-Fe-B films of 100 nm ≤ d ≤ 1000 nm were deposited on glass substrate by "flash" evaporation method. The structure and microstructure of the samples were studied by X-ray diffraction analysis, scanning electron microscopy. The temperature dependence of the magnetization before and after corrosion action was carried out by ponderomotive method in the temperature range 80 ≤ T ≤ 800 K. It is shown that the specific magnetizations of the thin Nd-Fe-B films with d ≥ 1000 nm are comparable to those measured for the powder samples. The values of the coercive and saturation fields were determined from the hysteresis loops measurements.

Źródło:

Acta Physica Polonica A; 2015, 127, 2; 368-370
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 10.

Tytuł:

Microscopic characteristic of Nd-Fe-B magnets structure - magnets recovered from electric motors

Autorzy:

Kapustka, K.
Ziegmann, G.
Sdrenka, S.
Elwert, T.
Klimecka-Tatar, D.

Powiązania:

https://bibliotekanauki.pl/articles/108989.pdf

Data publikacji:

2017

Wydawca:

Stowarzyszenie Menedżerów Jakości i Produkcji

Tematy:

NdFeB magnets
rare earth elements
microscopic analysis
structure of NdFeB
materiały magnetyczne twarde
struktura NdFeB
analiza mikroskopowa

Opis:

The rare earths (RE) are characterized with their strong metallic atomic bonds. They are used in magnetic materials used in computer technology and electric powered vehicles. The advancing globalization and the increasing standard of living both lead to massive waste disposal problems, therefore, the methods of recovering used metallic materials are sought. In this paper, the microscopic characteristic of magnetic powder from old electric engines has been presented.

Źródło:

Archiwum Wiedzy Inżynierskiej; 2017, 2, 1; 39-41
2544-2449

Pojawia się w:

Archiwum Wiedzy Inżynierskiej

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 11.

Tytuł:

Complex Characteristics of Sintered Nd-Fe-B Magnets in Terms of Hydrogen Based Recycling

Autorzy:

Szymański, M.
Michalski, B.
Leonowicz, M.
Miazga, Z.

Powiązania:

https://bibliotekanauki.pl/articles/1032966.pdf

Data publikacji:

2017-05

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

75.50.Ww

Opis:

Sintered Nd-Fe-B magnets, dismantled by the P.P.H.U. Polblume company from scrap hard disc drives and medical device, were thermally demagnetized and analyzed in terms of their chemical composition, structure and magnetic properties. Magnets from hard disc drives drives had a magnetic structure of two opposite poles in a plane of a magnet and were covered with a nickel coating (around 50 μ m in thick), which however was often discontinuous and deeply scratched. The majority of the magnets were partially destroyed (broken or corroded). The magnet from hard disc drives were basically made of iron (65±1 wt%) and neodymium (30±2 wt%) however, they also included alloying elements such as Co (1-2.5 wt%), Dy (0-1 wt%) or Pr (0-5 wt%). The magnets from medical device consisted only of iron (65±1 wt%) and neodymium (34±1 wt%). Magnets of both kinds were textured thus their XRD patterns were amended. Diffraction patterns, typical for the Nd₂Fe₁₄B (φ) phase, were achieved after mechanical crushing of the bulk magnets. A regular X-ray diffraction pattern was achieved after mechanical crushing of the magnets. The microstructure of both types of the magnets, observed by scanning electron microscopy, consisted of grey grains of a Nd₂Fe₁₄B (φ) phase and a Nd-rich grain boundary phase. The magnets from hard disc drives exhibited excellent magnetic properties and anisotropy: maximum energy product above 300 kJ/m³, remanence around 1.4 T and coercivity around 1000 kA/m, slightly varying between each magnet. Magnetic properties of medical magnet were only a little worse: maximum energy product above 200 kJ/m³, remanence around 1.1 T and coercivity around 900 kA/m. Hydrogen disproportionation phase diagrams (temperature vs. pressure) were constructed for both kinds of the magnets, revealing possible conditions for the hydrogenation, disproportionation, desorption and recombination reaction.

Źródło:

Acta Physica Polonica A; 2017, 131, 5; 1270-1273
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 12.

Tytuł:

Zastosowanie metod obliczeniowych do projektowania obwodów magnetycznych z dielektromagnesami Nd-Fe-B przeznaczonych do napędów elektrycznych
Application of mathematical methods to design magnetic circuits with Nd-Fe-B dielectromagnets for electrical drives

Autorzy:

Piotrowska-Kokot, E.
Ślusarek, B.

Powiązania:

https://bibliotekanauki.pl/articles/159244.pdf

Data publikacji:

2003

Wydawca:

Sieć Badawcza Łukasiewicz - Instytut Elektrotechniki

Tematy:

magnesy trwałe
napęd elektryczny

Opis:

Obecnie dobór magnesu do obwodu magnetycznego napędu elektromagnetycznego z podtrzymaniem magnesem trwałym, odbywa się na drodze testowania modelu. Doświadczenie konstruktora i dostępne na rynku materiały mają wpływ na rodzaj konstrukcji obwodu magnetycznego w takim napędzie. Współczesna technologia pozwala na wytwarzanie dielektromagnesów o oczekiwanych przez konstruktora właściwościach. Dotyczy to zarówno właściwości fizycznych, takich jak właściwości magnetyczne, mechaniczne, elektryczne i termiczne, ale także kształtu geometrycznego jak i topografii biegunów magnetycznych. Opracowany w Instytucie Elektrotechniki program wyznaczania charakterystyk dynamicznych z użyciem programu MatLab, umożliwia obliczanie złożonych obwodów magnetycznych napędów elektromagnetycznych. Program ten, wspomagany programem F!ux2D, pozwala na wytypowanie magnesu trwałego o optymalnych dla danej konstrukcji właściwościach fizycznych, kształcie i konfiguracji biegunów magnetycznych. Ułatwia to i skraca proces projektowania napędów elektrycznych przeznaczonych dla konkretnych urządzeń. W artykule przedstawiono dobór dielektromagnesów Nd-Fe-B przeznaczonych do obwodu magnetycznego wytypowanego napędu elektrycznego.
Presently the permanent magnet's selection for magnetic circuit of electromagnetic drive are performed by model testing. Designer's experience and materials accessible on the market decide of the construction of magnetic circuit in projected drive. Today's technology allows to produce dielectromagnets with properties requested by designer. Such possibility concern both physical properties of dielectromagnets as magnetic, mechanical, electrical and thermal properties and also shape and dimensions and magnet's poles configuration. Designed in Electrotechnical Institute computer programme with MatLab programme utilisation is intended to calculate the complicated magnetic circuits of electromagnetic drives. Such programme supported with Flux2D allows to select permanent magnet with physical properties, shape and poles configuration optimal for specific construction. It makes easier and cut short designing process of electric drives for specific devices. The papers present the selection of Nd-Fe-B dielectromagnets for magnetic circuit of some electrical drives.

Źródło:

Prace Instytutu Elektrotechniki; 2003, 216; 53-63
0032-6216

Pojawia się w:

Prace Instytutu Elektrotechniki

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 13.

Tytuł:

Microstructure and Properties of Magnets Obtained by Hydrostatic Extrusion of Nd-Fe-B Powder

Autorzy:

Gizynski, T.
Kaszuwara, W.
Pawlik, P.
Kulczyk, M.
Leonowicz, M.
Michalski, B.

Powiązania:

https://bibliotekanauki.pl/articles/1387955.pdf

Data publikacji:

2015-02

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

75.50.Ww

Opis:

Nd-Fe-B MQ powder was initially densified in a copper capsule to reach about 60% of the theoretical density. Subsequently, three various processes of hydrostatic extrusion were conducted at room temperature. The values of true strain, obtained during the all three stages, were 1.38, 0.89, 0.94, respectively. The investigation performed showed that the coercivity of the material decreases as the strain increases. Decrease of the remanence was observed only for the highest strains. Size of the particles was strongly reduced during the extrusion processes. X-ray diffraction did not show changes in the phase structure of the material. The Mössbauer study, of the sample extruded within all the three stages, showed existence of the Nd₂Fe₁₄B phase and 16% of other phase. Analysis of magnetization versus temperature confirmed that the additional phase was ferromagnetic.

Źródło:

Acta Physica Polonica A; 2015, 127, 2; 626-628
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 14.

Tytuł:

Control of Nd-Fe-B Morphology as Function of the PVP Concentration Using Electrospinning Process

Autorzy:

Eom, Nu Si A.
Haq, Muhammad Aneeq
Lee, Jimin
Lim, Kyoung Mook
Kim, Taek-Soo
Choa, Yong-Ho
Kim, Bum Sung

Powiązania:

https://bibliotekanauki.pl/articles/351180.pdf

Data publikacji:

2020

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

Nd2Fe14B
1-D magnet fiber
electrospinning
magnet properties
morphology

Opis:

In this study, we demonstrate a facile and cost-effective way to synthesize Nd-Fe-B of various shapes such as powders, rods and fibers using electrospinning, heat-treatment and washing procedures. Initially Nd-Fe-B fibers were fabricated using electrospinning. The as-spun Nd-Fe-B fibers had diameters ranging 489 to 630 nm depending on the PVP concentration in reaction solutions. The different morphologies of the Nd₂Fe₁₄B magnetic materials were related to the difference in thickness of the as-spun fibers. The relationships between the as-spun fiber thickness, the final morphology, and magnetic properties were briefly elucidated. The intrinsic coercivity of Nd₂Fe₁₄B changed with the change in morphology from powder (3908 Oe) to fiber (4622 Oe). This work demonstrates the effect of the Nd-Fe-B magnetic properties with morphology and can be extended to the experimental design of other magnetic materials.

Źródło:

Archives of Metallurgy and Materials; 2020, 65, 3; 993-996
1733-3490

Pojawia się w:

Archives of Metallurgy and Materials

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 15.

Tytuł:

Investigations of the magnetization reversal processes in nanocrystalline Nd-Fe-B alloys doped by Nb

Autorzy:

Kaźmierczak, M.
Pawlik, P.
Wysłocki, J.
Wnuk, I.
Gębara, P.
Pawlik, K.
Przybył, A.

Powiązania:

https://bibliotekanauki.pl/articles/1052622.pdf

Data publikacji:

2017-04

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

75.30.Sg
75.50.Bb

Opis:

In the following article the magnetic properties and phase composition of (Nd₁₀Fe₆₇B₂₃)_{100-x}Nb_{x} (where x=5, 6, 7, 8, 9) alloys in the form of ribbons are discussed. The X-ray diffraction studies revealed the coexistence of amorphous and nanocrystalline structures consisting of Nd₂Fe₁₄B, Nd_{1+ε}Fe₄B₄ and metastable Nd₂Fe₂₃B₃ phases. The shape of M_{rev} (M_{irr}) suggests that the magnetization reversal proceeds through the nucleation of the reversal domain for the ribbon doped with 5-7 at.% of Nb and the subsequent pinning of the domain walls for ribbons doped with 8 and 9 at.% of Nb.

Źródło:

Acta Physica Polonica A; 2017, 131, 4; 789-791
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 16.

Tytuł:

Effect Of The Desorption-Recombination Temperature On The Microstructure And Magnetic Properties Of HDDR Processed Nd-Fe-B Powders
Wpływ temperatury desorpcji-rekombinacji na mikrostrukturę i właściwości magnetyczne proszków Nd-Fe-B przetwarzanych metodą HDDR

Autorzy:

Lee, J.-G.
Cha, H.-R.
Liu, S.
Yu, J.-H.
Baek, Y.-K.
Kwon, H.-W.

Powiązania:

https://bibliotekanauki.pl/articles/353723.pdf

Data publikacji:

2015

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

Nd-Fe-B
HDDR
permanent magnet
grain boundary
metoda HDDR
magnes trwały
granica ziarna

Opis:

The effect of the desorption-recombination temperature on the microstructure and magnetic properties of hydrogenation-disproportionation-desorption-recombination (HDDR) processed Nd-Fe-B powders was studied. The Nd_xB_6.4Ga_0.3Nb₂0.2Fe_bal (x=12.5-13.5, at.%) casting alloys were pulverized after homogenizing annealing, and then subjected to HDDR treatment. During the HDDR process, desorption-recombination (DR) reaction was induced at two different temperature, 810°C and 820°C. The higher Nd content resulted in enhanced coercivity of the HDDR powder, and which was attributed to the thicker and more uniform Nd-rich phase along grain boundaries. But this uniform Nd-rich phase induced faster grain growth. The remanence of the powder DR-treated at 820°C is higher than that DR-treated at 810°C. In addition, it was also confirmed that higher DR temperature is much more effective to improve squareness.

Źródło:

Archives of Metallurgy and Materials; 2015, 60, 2B; 1499-1501
1733-3490

Pojawia się w:

Archives of Metallurgy and Materials

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 17.

Tytuł:

Effect of Powder Size on the Microstructure and Magnetic Properties of Nd-Fe-B Magnet Alloy

Autorzy:

Cho, Ju-Young
Abbas, Sardar Farhat
Choa, Yong-Ho
Kim, Taek-Soo

Powiązania:

https://bibliotekanauki.pl/articles/353634.pdf

Data publikacji:

2019

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

Nd-Fe-B
gas atomization
powder size
crystal orientation
hot deformation

Opis:

Rare earth Nd-Fe-B, a widely used magnet composition, was synthesized in a shape of powders using gas atomization, a rapid solidification based process. The microstructure and properties were investigated in accordance with solidification rate and densification. Detailed microstructural characterization was performed by using scanning electron microscope (SEM) and the structural properties were measured by using X-ray diffraction. Iron in the form of α-Fe phase was observed in powder of about 30 μm. It was expected that fraction of Nd₂ Fe₁₄ B phase increased rapidly with decrease in powder size, on the other hand that of α-Fe phase was decreased. Nd-rich phase diffused from grain boundary to particle boundary after hot deformation due to capillary action. The coercivity of the alloy decreased with increase in powder size. After hot deformation, Nd₂ Fe₁₄ B phase tend to align to c-axis.

Źródło:

Archives of Metallurgy and Materials; 2019, 64, 2; 623-626
1733-3490

Pojawia się w:

Archives of Metallurgy and Materials

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 18.

Tytuł:

Bezszczotkowy silnik prądu stałego o wzbudzeniu magnesami trwałymi przeznaczony do napędu wózków akumulatorowych
Brushless DC motor excited by permanent magnets for battery-electric trucks

Autorzy:

Ślusarek, B.
Gawryś, P.
Przybylski, M.
Czekała, T.

Powiązania:

https://bibliotekanauki.pl/articles/320269.pdf

Data publikacji:

2006

Wydawca:

Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH

Tematy:

silniki bezszczotkowe
komutator elektroniczny
magnesy Nd-Fe-B
permanent magnet brushless motor
electronic commutator
Nd-Fe-B permanent magnets

Opis:

W produkowanych obecnie wózkach akumulatorowych stosowane są silniki komutatorowe w wykonaniu szeregowym. Bezszczotkowe silniki prądu stałego zapewniają większą sprawność, trwałość i cichobieżność. Celem prowadzonych prac jest opracowanie, wykonanie i wdrożenie do produkcji bezszczotkowego silnika prądu stałego o mocy 8 kW przeznaczonego do wózków akumulatorowych produkowanych przez Fabrykę Maszyn w Leżajsku. W referacie przedstawiono zarysy projektu silnika wraz z układem sterowania o mocy 8 kW oraz wyniki badań wykonanego modelu silnika.
This paper deals with design, assembling and measurements of 8kW brushless DC motor for battery-electric trucks. The paper contains of measurements of flux density in air gap, load and efficiency curves. It contains also measured currents and voltages in windings of motor.

Źródło:

Elektrotechnika i Elektronika; 2006, 25, 2; 207-211
1640-7202

Pojawia się w:

Elektrotechnika i Elektronika

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 19.

Tytuł:

Characterization of Selected Parameters of Organic-Inorganic Hybrid Membranes Based on Various Polymers and Nd-Fe-B Fillers

Autorzy:

Rybak, A.
Kaszuwara, W.

Powiązania:

https://bibliotekanauki.pl/articles/352783.pdf

Data publikacji:

2016

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

organic-inorganic hybrid membranes
magnetic measurements
rheological parameters
mechanical properties
gas separation

Opis:

In this paper magnetic organic-inorganic hybrid membranes based on EC, PPO polymer matrices and various magnetic powder microparticles were synthesized and studied. Constant pressure permeation technique and the Time Lag method were used to obtain the gas transport coefficients. The mechanical, rheological and magnetic parameters of magnetic hybrid membranes were examined. It was found that their separation and gas transport properties (D, P, S and α) were improved with the decrease in powder particle size and the increase of membrane’s remanence, saturation magnetization and magnetic particle filling. The increase of the magnetic powder addition and a decrease of its granulation improved also mechanical and rheological parameters of the tested membranes. This improvement also had a positive effect on their gas separation properties and their potential usage in the future.

Źródło:

Archives of Metallurgy and Materials; 2016, 61, 4; 1825-1832
1733-3490

Pojawia się w:

Archives of Metallurgy and Materials

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 20.

Tytuł:

The Investigation of the Magnetization Reversal Mechanism in the Nd-Fe-B Type Magnet, Aligned by Hot Deformation

Autorzy:

Dośpiał, M.
Nabiałek, M.
Szota, M.
Lipiec, W.
Nizhankovskii, V.
Ceglarek, A.
Pietrusiewicz, P.

Powiązania:

https://bibliotekanauki.pl/articles/1429024.pdf

Data publikacji:

2012-05

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

75.30.Gw
75.30.Kz
75.50.Vv
75.50.Ww
75.60.Jk

Opis:

The magnetization reversal mechanism in the $Nd_{16}Fe_{78}B_6$ hot densified magnet, aligned by means of die-upset forging has been investigated. The magnetic parameters have been derived from major hysteresis loop. The magnetocrystalline anisotropy constants $K_1$ and $K_2$ using Sucksmith-Thompson relation modified by Ram and Gaunt have been calculated from the high field measurements up to 5 T. These data have been used to determine the theoretical value of coercivity as a function of the angle $Ψ_0$ between the sample easy axis and the applied magnetic field direction. The experimental value of coercivity as a function of $Ψ_0$ has been determined from the demagnetization curves measured for different $Ψ_0$ angles. It was found that the best correlation between theoretical and experimental data have been achieved for magnetization reversal mechanism controlled partially by pinning of domain walls on grain boundaries and nucleation processes.

Źródło:

Acta Physica Polonica A; 2012, 121, 5-6; 1282-1284
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 21.

Tytuł:

Influence of Additions and Stratification on the Magnetic Properties and Out-of-Plane Texture of Nd-Fe-B Films

Autorzy:

Grigoras, M.
Lupu, N.
Chiriac, H.
Borza, F.
Urse, M.

Powiązania:

https://bibliotekanauki.pl/articles/1368477.pdf

Data publikacji:

2014-07

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

75.30.Gw
75.50.Cc
75.50.Vv
75.70.Ak
75.70.Cn

Opis:

Nd-Fe-B films with Ta and Mo additions used as buffer and capping layers and as interlayers have been deposited by r.f. sputtering on heated Si(111) substrates at 370°C and 470°C, and subsequently annealed at temperatures between 550°C and 650°C. In comparison with the Ta/NdFeB/Ta film, the Mo/NdFeB/Mo film deposited at 470°C presents an obvious anisotropic character. Very good anisotropic magnetic properties were obtained for Mo/[NdFeB(180)/Mo(5)]×3/Mo multilayer film deposited at 470°C and then annealed at 550°C. This sample exhibits an increase in coercivity from 1225 kA/m up to 1651.8 kA/m, increase in $M_{r}$/$M_{s}$ ratio from 0.90 up to 0.99, and increase in the maximum energy product from 60.4 to 121.6 kJ/$m^{3}$ as compared to the as-deposited Mo/NdFeB/Mo film. The results demonstrate that after annealing at 550°C the Mo film is more effective for nucleation of $Nd_{2}Fe_{14}B$ hard magnetic grains with c-axis perpendicular to the film plane, especially in multilayer variant.

Źródło:

Acta Physica Polonica A; 2014, 126, 1; 220-221
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 22.

Tytuł:

Nanokrystaliczne, dwufazowe magnesy izotropowe otrzymywane metodą wysokoenergetycznego rozdrabniania - etap I
Nanocrystalline two phase isotropic magnets produced by HEBM method - stage I

Autorzy:

Lipiec, W.
Gaworska-Koniarek, D.
Ozimek, M.
Wilczyński, W.

Powiązania:

https://bibliotekanauki.pl/articles/160264.pdf

Data publikacji:

2010

Wydawca:

Sieć Badawcza Łukasiewicz - Instytut Elektrotechniki

Tematy:

magnes nanokrystaliczny
Nd-Fe-B
rozdrabnianie wysokoenergetyczne
odkształcanie na gorąco

Opis:

W artykule przedstawiono wyniki wstępnych prac wytwarzania nanokrystalicznych proszków metodą wysokoenergetycznego rozdrabniania. Wykorzystano je następnie jako surowiec do wytwarzania nanokrystalicznych magnesów neodymowych jednofazowych. Określono wpływ parametrów procesu mielenia, w dostępnym młynku kulowo-planetarnym, na morfologię i właściwości magnetyczne wytworzonych próbek magnesów. Wyniki prac pokazały, że stosując długotrwałe mielenie stopu Nd-Fe-B w młynku planetarno-kulowym możliwe jest wytworzenie proszków nanokrystalicznych, a nawet o amorficznej budowie cząstek. Nadmierne rozdrobnienie cząstek proszku i jego amorfizacja wpływa niekorzystnie na gęstość i właściwości magnetyczne magnesów otrzymywanych metodą zagęszczania na gorąco.
The paper presents the results of preliminary work of production process of nanocrystalline powders by high-energy ball milling. These powders then were used as raw materials for the manufacturing of single-phase nanocrystalline Nd-Fe-B magnets. The influence of the milling process parameters on the morphology and magnetic properties of produced magnets were examined. The results of the work have shown that applying long-term milling of Nd-Fe-B alloy allows to obtain nanocrystalline powders or even powders with amorphous structure of particles. However, overmilling of powder, which result is its amorphousation, adversely affects the density and magnetic properties of magnets produced with the use of hot densification method.

Źródło:

Prace Instytutu Elektrotechniki; 2010, 248; 97-114
0032-6216

Pojawia się w:

Prace Instytutu Elektrotechniki

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 23.

Tytuł:

Influence of heat treatment on magnetic properties of nanocrystalline Nd9Fe84Zr1B6 ribbons received by rapid solidification method
Wpływ obróbki termicznej na własności magnetyczne nanokrystalicznych taśm Nd9Fe84Zr1B6 wytwarzanych metodą szybkiego chłodzenia

Autorzy:

Ceglarek, A.
Płusa, D.
Pawlik, P.
Dośpiał, M.

Powiązania:

https://bibliotekanauki.pl/articles/354463.pdf

Data publikacji:

2012

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

nanokompozyty
metoda szybkiego chłodzenia
stopy Nd-Fe-B
twarde materiały magnetyczne
magnesy nanokrystaliczne
nanocomposites
rapid solidification method
Nd-Fe-B alloys
hard magnetic materials
nanocrystalline magnets

Opis:

The effect of the annealing on the phase composition and magnetic properties of nanocomposite melt-spun Nd9Fe84Zr1B6 ribbons has been investigated. From the X-ray diffraction studies confirmed be thermomagnetic curves measurements results that the microstructure of the material investigated is composed of a mixture of magnetically hard Nd2Fe14B and soft α-Fe, Fe3B nanosized grains. The small amount of undesirable Nd2Fe23B3 metastable phase has been found which do not decompose at the highest annealing temperature. The hysteresis loop measurements certify that the ribbon annealed at 863K show the best coupling between the hard and soft magnetic phases and thus the highest coercivity of 0.38T. The grain sizes increase with increasing annealing temperature causing the coercivity to be decrease.
Zbadano wpływ wygrzewania na skład fazowy i właściwości magnetyczne taśm nanokompozytowych Nd9Fe84Zr1B6 otrzymanych metodą szybkiego chłodzenia cieczy na wirującym miedzianym bębnie. Badania mikrostruktury potwierdzają zależności krzywych termomagnetycznych, z których wynika, że stop składa się z ziaren o rozmiarach nanometrycznych faz: magnetycznie miękkich α-Fe, Fe3B oraz magnetycznie twardej Nd2Fe14B. Stwierdzono niewielką ilość niepożądanej metastabilnej fazy, która nie ulega rozkładowi przy najwyższej temperaturze wygrzewania. Pomiary pętli histerezy magnetycznej dla taśmy wygrzanej w temperaturze 863K świadczą o najsilniejszych oddziaływaniach pomiędzy fazami, twardą i miękką. Rozmiar ziaren wzrasta we wzrostem temperatury wygrzewania, powodując spadek koercji. Koercja taśmy wygrzanej w temperaturze 863K ma największą wartość, wynoszącą 0.38T oraz najmniejszy rozmiar ziarna fazy Nd2Fe14B.

Źródło:

Archives of Metallurgy and Materials; 2012, 57, 1; 229-232
1733-3490

Pojawia się w:

Archives of Metallurgy and Materials

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 24.

Tytuł:

Fabrication of High-Strength Gray Cast Iron Using Permanent Magnet Scrap

Autorzy:

Park, S.-Y.
Kim, J. H.
Seo, S. J.
On, J. S.
Lim, K. M.

Powiązania:

https://bibliotekanauki.pl/articles/352204.pdf

Data publikacji:

2017

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

gray cast iron
rare earth element
Nd-Fe-B magnet scrap
graphite formation
microstructure

Opis:

In this study, we have developed the manufacturing technology for high strength gray cast irons by using the spent permanent magnet scraps. The cast specimen inoculated by using a spent magnet scraps showed the excellent tensile strength up to 306MPa. This tensile strength value is 50MPa higher than that of the specimen cast without inoculation, and is similar to that of the specimen inoculated by using the expensive misch-metal. These superior mechanical properties are attributed to complex sulfides created during solidification that promote the formation and growth of Type-A graphite. It is therefore concluded that spent magnets scrap can provide an efficient and cost-effective inoculation agent for the fabrication of high-performance gray cast iron.

Źródło:

Archives of Metallurgy and Materials; 2017, 62, 2B; 1113-1117
1733-3490

Pojawia się w:

Archives of Metallurgy and Materials

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 25.

Tytuł:

Influence of Nb Addition on Magnetic Properties of the Nanocrystalline $(Nd₁₀Fe₆₇B₂₃)_{100-x}Nbₓ$ (where x = 1, 2, 4) Alloy Ribbons

Autorzy:

Szwaja, M.
Pawlik, K.
Pawlik, P.
Gębara, P.
Michalski, B.

Powiązania:

https://bibliotekanauki.pl/articles/1387907.pdf

Data publikacji:

2015-02

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

75.20.En
75.75.-c
75.75.Cd

Opis:

In the present work the magnetic properties and phase constitution of $(Nd₁₀Fe₆₇B₂₃)_{100-x}Nbₓ$ (where x = 1, 2, 4) alloys in the form of ribbons were investigated. The base alloys were prepared by arc-melting the high purity elements with pre-alloyed Fe-B under an Ar atmosphere. The ribbon samples were obtained by controlled atmosphere melt-spinning technique. In order to generate the nanocrystalline microstructure and hard magnetic properties, samples were annealed at various temperatures (from 923 K to 1023 K) for 5 min. The aim of the present work was to determine the influence of Nb admixture and annealing conditions on the phase constitution and magnetic properties.

Źródło:

Acta Physica Polonica A; 2015, 127, 2; 623-625
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 26.

Tytuł:

The Effect of Powder Particle Biencapsulation with Ni-P Layer on Local Corrosion of Bonded Nd-(Fe,Co)-B Magnetic Material
Bienkapsulacja cząstek proszku powłokami Ni-P jako sposób poprawy odporności wiązanych magnesów Nd-(Fe,Co)-B na korozję lokalną

Autorzy:

Klimecka-Tatar, D.
Pawłowska, G.
Sozańska, M.

Powiązania:

https://bibliotekanauki.pl/articles/352049.pdf

Data publikacji:

2015

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

Nd-Fe-B bonded magnets
biencapsulation
local corrosion
Ni-P layers
magnes wiązany
bienkapsulacja
korozja
powłoki Ni-P

Opis:

Effect of the Nd-(Fe,Co)-B powder particle biencapsulation with Ni-P layer on bonded magnetic materials corrosion behaviour has been investigated. Bonded magnets were prepared from single-phase, nanocrystalline magnetic Nd₁₁ Fe₇₇ Co₅ B₆ powder. Powder particles before consolidation were preliminary etched and then coated with bilayer (powder biencapsulation). The powder surface was coated as a first with autocatalytic applied Ni-P layer during 5, 15 and 30 minutes in Ni(II) containing bath and the second layer was thermosetting epoxy-resin. Impact of the used biencapsulation process was rated on the basis of polarization curves recorded in phosphate environment with addition of chloric ions. It has been established that the used biencapsulation method satisfactorily isolate individual particles of the powder and consequently, significantly inhibits corrosion processes of the final material, especially in passivating environment containing Cl^-.
W pracy zaprezentowano wyniki badań nad wpływem bienkapsulacji cząstek proszku powłokami Ni-P/żywica epoksy-dowan na odporność korozyjną magnesów wiązanych. Materiały magnetyczne zostały przygotowane z jednofazowego, na-nokrystalicznego proszku Nd₁₁ Fe₇₇ Co₅ B₆. Cząstki proszku przed konsolidacją były wstępnie trawione, a następnie pokryte podwójną warstwą (bienkapsulacja proszku). Powierzchnia proszku w pierwszej kolejności została poddana 5 i 30 minutowemu autokatalitycznemu nanoszeniu warstw Ni-P. Drugą warstwę stanowił materiał spoiwa, czyli żywica epoksydowa. Dokonano oceny wpływu zastosowanej metody bienkapsulacji na odporność na korozję lokalną na podstawie krzywych polaryzacji zarejestrowanych w środowisku fosforanowym (0,5M, pH = 3) z dodatkiem jonów chlorowy. Stwierdzono, że zastosowane metody bienkapsulacji zadowalająco izolują pojedyncze cząstki proszku, a co za tym idzie, hamują proces korozji materiału końcowego, zwłaszcza w środowisku pasywującym zawierającym Cl^- .

Źródło:

Archives of Metallurgy and Materials; 2015, 60, 1; 153-157
1733-3490

Pojawia się w:

Archives of Metallurgy and Materials

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 27.

Tytuł:

Microstructure and Magnetic Properties of NdFeB Sintered Magnets Diffusion-Treated with Cu/Al Mixed Dyco Alloy-Powder

Autorzy:

Lee, M.-W.
Bae, K.-H.
Lee, S.-R.
Kim, H.-J.
Jang, T.-S.

Powiązania:

https://bibliotekanauki.pl/articles/353351.pdf

Data publikacji:

2017

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

Nd-Fe-B sintered magnets
grain boundary diffusion process
low melting point element
DyCo alloy-powder diffusion

Opis:

We investigated the microstructural and magnetic property changes of DyCo, Cu + DyCo, and Al + DyCo diffusion-treated NdFeB sintered magnets. The coercivity of all diffusion treated magnet was increased at 880ºC of 1st post annealing(PA), by 6.1 kOe in Cu and 7.0 kOe in Al mixed DyCo coated magnets, whereas this increment was found to be relatively low (3.9 kOe) in the magnet coated with DyCo only. The diffusivity and diffusion depth of Dy were increased in those magnets which were treated with Cu or Al mixed DyCo, mainly due to comparatively easy diffusion path provided by Cu and Al because of their solubility with Ndrich grain boundary phase. The formation of Cu/Al-rich grain boundary phase might have enhanced the diffusivity of Dy-atoms. Moreover, relatively a large number of Dy atoms reached into the magnet and mostly segregated at the interface of Nd₂ Fe₁₄ B and grain boundary phases covering Nd₂ Fe₁₄ B grains so that the core-shell type structures were developed. The formation of highly anisotropic (Nd, Dy)₂Fe₁₄B phase layer, which acted as the shell in the core-shell type structure so as to prevent the reverse domain movement, was the cause of enhancing the coercivity of diffusion treated NdFeB magnets. Segregation of cobalt in Nd-rich TJP followed by the formation of Co-rich phase was beneficial for the coercivity enhancement, resulting in the stabilization of the metastable c-Nd₂O₃ phase.

Źródło:

Archives of Metallurgy and Materials; 2017, 62, 2B; 1263-1266
1733-3490

Pojawia się w:

Archives of Metallurgy and Materials

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 28.

Tytuł:

The domain structure of die-upset anisotropic magnet based on Nd-(Fe, Co)-B alloy
Struktura domenowa anizotropowego odkształconego na gorąco magnesu na bazie związku Nd-(Fe, Co)-B

Autorzy:

Płusa, D.
Dośpial, M.
Derewnicka-Krawczyńska, D.
Wieczorek, P.
Kotlarczyk, U.

Powiązania:

https://bibliotekanauki.pl/articles/354074.pdf

Data publikacji:

2011

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

exchange interactions
high coercivity materials
permanent magnets
domain walls and domain structure

Opis:

The measurements of the recoil curves for the die-upset Nd-(Fe, Co)-B based magnets from different points on the magnetization and demagnetization curves have been carried out by means of the LakeShore vibrating sample magnetometer in an applied magnetic fields up to 2 T. From the recoil curves the so-called Wohlfarth's remanence relationship has been derived. From this it was deduced that the magnetic interaction existing between the magnet grains has a dipolar nature. The existence of the magnetic interaction has been confirmed by magnetic domain observations by using the magnetic force microscopy (MFM). In the area of interaction domains there is the fine scale magnetic contrast resulting from the dipolar interaction between neighboring grains.
Za pomocą magnetometru wibracyjnego firmy LakeShore wyznaczono krzywe powrotne dla spęczanych magnesów Nd-(Fe, Co)-B w polu magnetycznym do 2 T. Na podstawie krzywych powrotnych wyznaczono zależność remeanencyjną Wohlfartha. Z zależności tej wynika, że oddziaływania magnetyczne pomiędzy ziarnami to dalekozasięgowe oddziaływania dipolowe. Obecność tych oddziaływań została potwierdzona przez obserwację struktury domenowej za pomocą mikroskopu sił magnetycznych (MFM). Oscylacyjne zmiany kontrastu, występujące w obszarach zbliżonych do wielkości ziaren, świadczą o istnieniu uporządkowania magnetycznego w tych obszarach, które jest wynikiem oddziaływania dipolowego między sąsiednimi ziarnami.

Źródło:

Archives of Metallurgy and Materials; 2011, 56, 1; 159-161
1733-3490

Pojawia się w:

Archives of Metallurgy and Materials

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 29.

Tytuł:

Effect Of DyMn Alloy-Powder Addition On Microstructure And Magnetic Properties Of NdFeB Sintered Magnets
Wpływ dodatku proszku DyMn na mikrostrukturę i właściwości magnetyczne spiekanych magnesów NdFeB

Autorzy:

Lee, M.-W.
Dhakal, D. R.
Kim, T. H.
Lee, S. R.
Kim, H. J.
Jang, T. S.

Powiązania:

https://bibliotekanauki.pl/articles/357010.pdf

Data publikacji:

2015

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

Nd-Fe-B sintered magnets
DyMn-alloy powder
coercivity
low melting point element
magnesy spiekane
proszek DyMn
koercja
elementy o niskiej temperaturze topnienia

Opis:

Micostructural change and corresponding effect on coercivity of a NdFeB sintered magnet mixed with small amount of DyMn powder was investigated. In the sintered magnet mixed with the DyMn alloy-powder Dy-rich shell was formed at outer layer of the main grains, while Mn was mostly concentrated at Nd-rich triple junction phase (TJP), lowering melting temperature of the Nd-rich phase that eventually improved the microstructural characteristics of the gain boundary phase. The coercivity of a magnet increased more than 3.5 kOe by the mixing of the DyMn alloy-powder.

Źródło:

Archives of Metallurgy and Materials; 2015, 60, 2B; 1407-1409
1733-3490

Pojawia się w:

Archives of Metallurgy and Materials

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 30.

Tytuł:

Magnetic Properties of $Nd_{12}Fe_{82}B_6$ and $Nd_{14}Fe_{80}B_6$ Powders Obtained by High Temperature Milling

Autorzy:

Kaszuwara, W.
Michalski, B.

Powiązania:

https://bibliotekanauki.pl/articles/1490856.pdf

Data publikacji:

2012-01

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

75.50.Tt
75.50.Ww
81.20.Wk

Opis:

The present paper describes a comparison of magnetic properties of $Nd_{12}Fe_{82}B_6$ and $Nd_{14}Fe_{80}B_6$ powders obtained by a new method of processing of Nd-Fe-B powders - high temperature milling. In this method the milling operation is carried out, entirely or only in the final stage, at high temperatures, so that the destruction of the $Nd_2Fe_{14}B$ phase and its recombination occur simultaneously. In this way a powder with good magnetic properties immediately after milling was obtained. In the present experiments, the powder was subjected to high-energy milling for 17 h (until the material becomes amorphous) and then, the milling was continued for 0.5 h with the powder container being heated to an appropriate temperature or milled at high temperature during whole time of the process. Diffraction examinations have shown that the powder processed in this way contains the $Nd_2Fe_{14}B$ phase. Its magnetic properties appear to depend on the applied temperature or milling time (at optimum temperature). The used method of processing leads to obtaining high-coercivity Nd-Fe-B powders. The magnetic properties of the material thus produced, in particular its coercivity, strongly depend on the milling temperature and milling time.

Źródło:

Acta Physica Polonica A; 2012, 121, 1; 89-93
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 31.

Tytuł:

Mössbauer study of treated Nd2Fe14B

Autorzy:

Budzyński, M.
Constantin, V. C.
Popescu, A.-N. J.
Surowiec, Z.
Tkachenka, T. M.
Yanushkevich, K. I.

Powiązania:

https://bibliotekanauki.pl/articles/146270.pdf

Data publikacji:

2015

Wydawca:

Instytut Chemii i Techniki Jądrowej

Tematy:

intermetallics
intergranular corrosion
Mössbauer spectroscopy

Opis:

The Nd2Fe14B cylindrical magnets were treated with water solutions of alkali, acid, and salt. Mössbauer spectroscopy was applied to study the composition and properties of the surface material of the treated magnets. It is shown that the main phase of the permanent Nd2Fe14B magnet partly decomposes. The released α-Nd at the grain boundaries interacts with water and forms neodymium hydroxide matrix, and the released Fe diffuses into it. The presence of Fe-Nd(OH)3 is refl ected in the paramagnet doublet in the Mössbauer spectra of treated neodymium magnets.

Źródło:

Nukleonika; 2015, 60, 1; 7-10
0029-5922
1508-5791

Pojawia się w:

Nukleonika

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 32.

Tytuł:

Effect of Mg Ratio on the Extraction of Dy from (Nd,Dy)-Fe-B Permanent Magnet Using Liquid Mg

Autorzy:

Park, Sang-Min
Nam, Sun-Woo
Cho, Ju-Young
Lee, Sang-Hoon
Hyun, Seung-Keun
Kim, Taek-Soo

Powiązania:

https://bibliotekanauki.pl/articles/353657.pdf

Data publikacji:

2020

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

dysprosium
liquid metal extraction
(Nd,Dy)-Fe-B magnet
extraction behavior
diffusion

Opis:

Recently, since the demand of rare earth permanent magnet for high temperature applications such as an electric motor has increased, dysprosium (Dy), a heavy rare earth element, is becoming important due to severe bias in its production. To fulfillthe increasing need of Dy, recycling offers as a promising alternative. In recycling of rare earths, Hydro-metallurgical extraction method is mainly used however it has adverse environmental effects. Liquid metal extraction on the other hand, is an eco-friendly and simple method as far as the reduction of rare earth metal oxide is concerned. Therefore, liquid metal extraction was studied in this research as an alternative to the hydro-metallurgical recycling method. Magnesium (Mg) is selected as solvent metal because it doesn’t form intermetallic compounds with Fe, B and has a low melting and low boiling point. Extraction behavior of Dy in (Nd,Dy)-Fe-B magnet is observed and effect of Mg ratio on extraction of Dy is confirmed.

Źródło:

Archives of Metallurgy and Materials; 2020, 65, 4; 1281-1285
1733-3490

Pojawia się w:

Archives of Metallurgy and Materials

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 33.

Tytuł:

The Magnetization Reversal Processes of Bulk (Nd, Y)‑(Fe, Co)‑B Alloy in the As-Quenched State
Procesy przemagnesowania masywnych stopów (Nd, Y)‑(Fe, Co)‑B w stanie po zestaleniu

Autorzy:

Dośpiał, M.
Nabiałek, M.
Szota, M.
Gondro, J.

Powiązania:

https://bibliotekanauki.pl/articles/356998.pdf

Data publikacji:

2015

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

magnetization reversal
hard magnetic materials
nanomaterials
odwrócenie magnesowania
twarde materiały magnetyczne
nanomateriały

Opis:

The magnetization reversal processes of bulk Fe₆₄Co₅Nd₆Y₆B₁₉ alloy in the as-quenched state have been investigated. From the analysis of the initial magnetization curve and differential susceptibility versus an internal magnetic field it was deduced, that the main mechanism of magnetization reversal process is the pinning of domain walls at the grain’s boundaries of the Nd2Fe14B phase. Basing on the dependence of the reversible magnetization component as a function of magnetic field it was found that reversible rotation of a magnetic moment vector and motion of domain walls in multi-domain grains result in high initial values of the reversible component. The presence of at least two maxima on differential susceptibility of irreversible magnetization component in function of magnetic field imply existence of few pinning sites of domain walls in Fe₆₄Co₅Nd₆Y₆B₁₉ alloy. The dominant interactions between particles have been determined on the basis of the Wohlfarth dependence. Such a behavior of Wohlfarth’s plot implies that the dominant interaction between grains becomes short range exchange interactions.
W pracy przedstawiono wyniki badań własności magnetycznych i mechanizmów przemagnesowania masywnego stopu Fe₆₄Co₅Nd₆Y₆B₁₉ w stanie po zestaleniu. Z krzywych pierwotnego namagnesowania i ich podatności różnicowej określono, że głównym mechanizmem przemagnesowania jest kotwiczenie ścian domenowych. Na podstawie zależności składowych odwracalnych namagnesowania od pola magnetycznego stwierdzono, że procesy odwracalne takie jak obroty wektora namagnesowania oraz ruch ścian domenowych w wielodomenowych ziarnach mają znaczny wpływ na zmiany namagnesowania dla początkowych wartości pól magnetycznych. Obecność maksimów w zależności składowej nieodwracalnej podatności magnetycznej świadczy, że głównym mechanizmem przemagnesowania w badanych magnesach jest kotwiczenie ścian domenowych na licznych centrach kotwiczenia znajdujących się na granicach ziaren fazy Nd₂Fe₁₄B oraz na defektach strukturalnych. W celu określenia oddziaływań między ziarnami określono zależność Wohlfartha. Zależność ta nie jest spełniona dla badanego magnesu, świadczy to o istnieniu oddziaływania wymiennego między ziarnami magnesu.

Źródło:

Archives of Metallurgy and Materials; 2015, 60, 3A; 1587-1590
1733-3490

Pojawia się w:

Archives of Metallurgy and Materials

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 34.

Tytuł:

Phase structure of the nanocrystalline Nd2Fe14B/alfa-Fe magnets with different grain

Autorzy:

Wnuk, I.
Wysłocki, J.
Przybył, A.

Powiązania:

https://bibliotekanauki.pl/articles/148342.pdf

Data publikacji:

2007

Wydawca:

Instytut Chemii i Techniki Jądrowej

Tematy:

Nd2Fe14B + alfa-Fe nanocrystalline magnets
Mössbauer spectroscopy
magnetic properties

Opis:

The effect of the contents of the magnetically hard and magnetically soft phases on the magnetic properties of Nd2Fe14B + alfa-Fe nanocrystalline magnets, as produced by the method of mechanical alloying, has been established. The phase composition of specimens was determined using X-ray diffractometry and Mössbauer spectroscopy. The Mössbauer examination showed that as the powder milling times increased, the content of the Nd2Fe14B phase increased from 42.8% (after the milling time of 10 h, with a grain size of 44.8 nm) to 66.3% (after the milling time of 48 h, with a grain size of 37.3 nm) and then decreased to 40.3% after 120 h of milling. On the other hand, the content of the magnetically soft phase alfa-Fe initially decreased (from 27.7%), reaching a minimum after the milling time of 48 h (17.4%) and then increasing to 36.9% after 120 h of milling.

Źródło:

Nukleonika; 2007, 52, supl. 1; 85-88
0029-5922
1508-5791

Pojawia się w:

Nukleonika

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 35.

Tytuł:

Characterization of phase constitution and magnetic properties of the hard magnetic nanocrystalline Nd9.5Fe63.65B21.85Nb5 alloy ribbons

Autorzy:

Szwaja, M.
Pawlik, K.
Wysłocki, J. J.
Pawlik, P.
Gębara, P.

Powiązania:

https://bibliotekanauki.pl/articles/147840.pdf

Data publikacji:

2013

Wydawca:

Instytut Chemii i Techniki Jądrowej

Tematy:

magnetic properties NdFeB alloys
nanocrystalline ribbon
Nd2Fe14B
X-ray diffractometry

Opis:

In order to investigate the phase constitution of the nanocrystalline Nd9.5Fe63.65B21.85Nb5 alloy ribbons in the as-cast state and after short-time annealing Mossbauer study has been carried out. In as-cast state, ribbon samples were not fully amorphous but revealed soft magnetic properties. X-ray diffraction analysis showed the presence of hard magnetic Nd2Fe14B, metastable Nd2Fe23B3 and paramagnetic Nd1+epsilonFe4B4 phases in annealed samples. Mossbauer spectroscopy was used to determine the fractions of constituent phases formed during annealing of ribbons. Magnetic measurements were made with a vibrating sample magnetometer (VSM) and have shown that with increasing annealing temperature the remanence polarization Jr and maximum energy product (BH)max values were increasing.

Źródło:

Nukleonika; 2013, 58, 1; 159-163
0029-5922
1508-5791

Pojawia się w:

Nukleonika

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 36.

Tytuł:

Effect of Preparing Conditions on the Phase Constitution and Magnetic Properties of Nd-Pr-Fe-Zr-B Alloy Ribbons

Autorzy:

Ceglarek, A.
Gębara, P.
Płusa, D.

Powiązania:

https://bibliotekanauki.pl/articles/1387200.pdf

Data publikacji:

2015-02

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

75.30.Et
91.60.Pn

Opis:

The aim of presented work was to study influence of preparing conditions on phase constitution and magnetic properties of the RE-Fe-B nanocomposite magnets doped with Zr. X-ray studies carried out for samples obtained under lower pressure of Ar atmosphere (0.6×10⁵ Pa) revealed higher ability to formation of nanocrystalline structure. In case of higher pressure of Ar (0.8×10⁵ Pa) it was possible to obtain full amorphous ribbon during melt-spinning process. The best magnetic properties (means the higher values of coercivity field $\text{}_{J}H_{c}$, remanence $J_{r}$ and maximum energy product $(BH)_{max})$ were measured for sample prepared with the lowest copper wheel speed 20 m/s and higher pressure of Ar (0.8×10⁵ Pa).

Źródło:

Acta Physica Polonica A; 2015, 127, 2; 570-572
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 37.

Tytuł:

Thermomagnetic Behaviour and Microstructure of a Rapidly Quenched $Nd_{4.5}Fe_{77}B_{18.5}$ Alloy

Autorzy:

Talijan, N.
Ćosović, V.
Grujić, A.
Stajić-Trošić, J.
Žák, T.

Powiązania:

https://bibliotekanauki.pl/articles/1813871.pdf

Data publikacji:

2008-01

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

81.40.Rs

Opis:

Changes in the phase composition and crystallite size, as well as changes in the magnetic behaviour of $Nd_{4.5}Fe_{77}B_{18.5}$ alloy, caused by thermomagnetic measurements, was observed in regard of the optimal magnetic state of this alloy. In the optimized magnetic state, the formed nanocomposite consisted of $Fe_3B//Nd_2Fe_{14}B$ and partly of α-Fe with a mean crystallite size < 30 nm, as determined by X-ray diffraction and transmission electron microscopy. An increased amount of α-Fe, the presence of $Nd_2O_3$ and different Fe-B phases, as well as an increase in the mean crystallite size were observed after thermomagnetic measurements had caused a quality loss of the hard magnetic properties.

Źródło:

Acta Physica Polonica A; 2008, 113, 1; 525-528
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 38.

Tytuł:

Magnetic properties of the nanocrystalline Nd9.6Fe64.32Nb4B22.08 alloy ribbons
Właściwości magnetyczne nanokrystalicznych taśm stopu Nd9,6Fe64,32Nb4B22,08

Autorzy:

Szwaja, M.
Pawlik, P.
Wysłocki, J. J.
Gębara, P.

Powiązania:

https://bibliotekanauki.pl/articles/354465.pdf

Data publikacji:

2012

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

dyfraktometria promieniowania X
właściwości magnetyczne stopu NdFeB
Nd2Fe14B
taśma nanokrystaliczna
X-ray diffractometry
magnetic properties NdFeB alloys
nanocrystalline ribbon

Opis:

Studies of magnetic properties and phase constitution of nanocrystalline Nd9.6Fe64.32Nb4B22.08 alloy ribbon samples are presented. In as-cast state, ribbon samples were fully amorphous and soft magnetic. Subsequent annealing resulted in an evolution of the phase constitution together with change of their magnetic properties. The main phase observed in the material is Nd2Fe14B hard magnetic phase.
W pracy badano własności magnetyczne oraz skład fazowy taśm wytworzonych ze stopu Nd9,6Fe64,32Nb4B22,08. Taśma w stanie po odlaniu ma amorficzną budowę i wykazuje miękkie właściwości magnetyczne. Wygrzewanie taśm powoduje zmiany składu fazowego wraz ze zmianą ich właściwości magnetycznych. Podstawową fazą obserwowaną w badanym materiale jest faza magnetycznie twarda Nd2Fe14B.

Źródło:

Archives of Metallurgy and Materials; 2012, 57, 1; 233-236
1733-3490

Pojawia się w:

Archives of Metallurgy and Materials

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 39.

Tytuł:

Magnetic Properties and Phase Constitution of the Nanocrystalline $(Nd_{10}Fe_{67}B_{23})_{100-x}Nb_{x}$ (where x=1, 2, 3, 4) Alloy Ribbons

Autorzy:

Kaźmierczak, M.
Pawlik, K.
Pawlik, P.
Gębara, P.
Przybył, A.
Wysłocki, J.

Powiązania:

https://bibliotekanauki.pl/articles/1402329.pdf

Data publikacji:

2015-07

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

75.20.En
91.60.Pn

Opis:

In the present work the magnetic properties and phase constitution of $(Nd_{10}Fe_{67}B_{23})_{100-x}Nb_{x}$ (where x=1, 2, 3, 4) alloys in a form of ribbons were investigated. The ribbon samples were obtained by controlled atmosphere melt-spinning technique. In order to generate the nanocrystalline microstructure, ribbons were annealed at various temperatures (from 923 K to 1023 K) for 5 min. Subsequent annealing resulted in an evolution of the phase constitution accompanied by a change of their magnetic properties. The X-ray diffraction studies show presence of hard magnetic $Nd_{2}Fe_{14}B$, paramagnetic $Nd_{1+\epsilon}Fe_{4}B_{4}$ and ferromagnetic metastable $Nd_{2}Fe_{23}B_{3}$ phases. The best hard magnetic parameters were measure for annealed ribbons of the $(Nd_{10}Fe_{67}B_{23})_{96}Nb_{4}$ alloy.

Źródło:

Acta Physica Polonica A; 2015, 128, 1; 91-93
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 40.

Tytuł:

Stark and Zeeman Effects in Nd$\text{}_{2}$Fe$\text{}_{14}$B and Pr$\text{}_{2}$Fe$\text{}_{14}$B Intermetallics

Autorzy:

Radwański, R. J.
Franse, J. M.

Powiązania:

https://bibliotekanauki.pl/articles/1945558.pdf

Data publikacji:

1996-07

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

71.70.Ej
75.10.Dg

Opis:

The energy level scheme of the Nd$\text{}^{3+}$ and Pr$\text{}^{3+}$ ions in ferromagnetic Nd$\text{}_{2}$Fe$\text{}_{14}$B and Pr$\text{}_{2}$Fe$\text{}_{14}$B intermetallic compounds was evaluated on the basis of all known experiments. In calculations the effect of charge (Stark effect) and spin-dependent (Zeeman effect) interactions were taken into account by means of the crystal-field and molecular-field approximation, respectively. The derived energy level scheme is associated with the removal of the degeneracy of the lowest multiplet given by Hund's rules, i.e. $\text{}^{4}$I $\text{}_{9}\text{}_{/}\text{}_{2}$ (Nd$\text{}^{3+}$) and $\text{}^{3}$H$\text{}_{4}$ (Pr$\text{}^{3+}$). The revealed low-energy electronic structure (<25 meV = 200 cm$\text{}^{-1}$) is associated with many-electron states of the RE$\text{}^{3+}$ ions. Magnetic and electronic properties resulting from this fine structure are compared with all known experimental results. The localized crystal electric field levels exist also in Nd$\text{}_{2}$CuO$\text{}_{4}$, an ionic compound which by doping with Ce becomes high-T$\text{}_{c}$ superconductor, indicating the formation of crystal electric field states independently on the metallic or ionic state.

Źródło:

Acta Physica Polonica A; 1996, 90, 1; 223-232
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 41.

Tytuł:

Dependence of the Structure And Magnetic Properties of Cast Plate-Shaped Nd60Fe30Al10 Samples on Their Thickness
Zależność mikrostruktury i właściwości magnetycznych od grubości magnesów Nd60Fe30Al10 odlewanych w postaci płytek

Autorzy:

Michalski, B.
Kaszuwara, W.
Latuch, J.
Pawlik, P.

Powiązania:

https://bibliotekanauki.pl/articles/356812.pdf

Data publikacji:

2015

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

hard magnetic materials
Nd-Fe-Al alloys
rapid quenching
twarde materiały magnetyczne
szybkie hartowanie

Opis:

The hard magnetic Nd-Fe-Al alloys are inferior to Nd-Fe-B magnets as far as the magnetic properties are concerned, but their great advantage is that they need no additional annealing to achieve good magnetic properties. These properties depend on the cooling rate from the melting state, and on the thickness of the sample - the best values are achieved at the quenching rates at which the samples have a thickness of 0.3-2 mm. The present study is concerned with the correlation between the magnetic properties of the plate-shaped Nd₆₀Fe₃₀Al₁₀ samples and their size - thickness. Two casting ways: with the melt stream perpendicular direction and parallel to the surface of the plates were used. The plates were produced by pressure casting and suction casting. The studies have shown that the cooling rates depends on local propagation on liquid metal in the mold resulting in heterogeneity of structure and properties.
Stopy Nd-Fe-Al nie posiadają tak wysokich właściwości magnetycznych jak Nd-Fe-B. Ich dużą zaletą jest natomiast możliwość otrzymywania bezpośrednio poprzez odlewanie. Właściwości magnetyczne zależą od szybkości chłodzenia ciekłego stopu, co w praktyce określa się rozmiarem odlewanej próbki. Przy odlewaniu do form metalowych optymalny zakres wymiaru w kierunku odprowadzania ciepła to 0,3-2 mm. W niniejszej pracy zbadano zależność właściwości magnetycznych stopu Nd₆₀Fe₃₀Al₁₀ od grubości próbek w postaci płytek w zależności od sposobu odlewania (wtryskiwanie cieczy pod ciśnieniem i odlewanie z zasysaniem) oraz kierunku strumienia cieczy (prostopadle lub równolegle do powierzchni płytki). Badania wykazały, że szybkość chłodzenia zależy lokalnie od sposobu rozchodzenia się cieczy w formie, co skutkuje niejednorodnością mikrostruktury i właściwości.

Źródło:

Archives of Metallurgy and Materials; 2015, 60, 3A; 1623-1627
1733-3490

Pojawia się w:

Archives of Metallurgy and Materials

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 42.

Tytuł:

Investigation of the Magnetization Reversal Process of High-Remanent $Nd_{10}Fe_{83}Zr_1B_6$ Alloy in the As-Cast State

Autorzy:

Ceglarek, A.
Płusa, D.
Dośpiał, M.
Nabiałek, M.
Pietrusiewicz, P.

Powiązania:

https://bibliotekanauki.pl/articles/1429022.pdf

Data publikacji:

2012-05

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

75.30.Et
75.50.Vv
75.50.Ww
75.60.Ej
75.60.Jk

Opis:

In this work the magnetic properties of ribbons with composition of $Nd_{10}Fe_{83}Zr_1B_6$ obtained by using the melt-spinning method were studied. From the X-ray diffraction patterns the phase composition was determined. It was found that investigated alloy was composed of α-Fe and $Nd_2Fe_{14}B$ phases. From the peaks broadening the grain sizes of α-Fe and $Nd_2Fe_{14}B$ phases were estimated as equal to 20 nm and 40 nm, respectively. From the recoil curves the reversible $μ_0$ $M_{rev}$ and irreversible $μ_0 M_{irr}$ parts of magnetization and differential susceptibility $χ_{rev}$ and $χ_{irr}$ were determined as a function of an applied field. From these dependences it was found that the pinning of domain walls at the grain boundaries is the main magnetization reversal process. The interactions between grains were investigated by means of the δ M plot. It was stated that short range exchange interaction between grains of hard and soft phases are dominant and causes the remanence enhancement.

Źródło:

Acta Physica Polonica A; 2012, 121, 5-6; 1279-1281
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 43.

Tytuł:

Structural and magnetic properties of the as - cast Nd10Fe83Zr1B6 ribbons, studied by X-ray diffraction and Mössbauer spectroscopy

Autorzy:

Ceglarek, A.
Płusa, D.
Pawlik, P.
Gębara, P.

Powiązania:

https://bibliotekanauki.pl/articles/147920.pdf

Data publikacji:

2013

Wydawca:

Instytut Chemii i Techniki Jądrowej

Tematy:

hard magnetic magnets
melt-spinning technique
Mössbauer spectroscopy
nanocomposites

Opis:

The Nd10Fe83Zr1B6 alloy ribbons, prepared by melt-spinning technique, have been investigated by X-ray diffraction (XRD) and Mossbauer spectroscopy. Magnetic properties were studied by Faraday balance and vibrating sample magnetometry (VSM). The ribbon samples were produced at various surface velocities of the copper wheel from 10 m/s to 20 m/s. The XRD and Mossbauer spectra analysis have shown that the ribbons consist of the soft magnetic alfa-Fe, hard magnetic Nd2Fe14B and disordered phases. The results showed that a uniform Nd2Fe14B/alfa-Fe nanocomposite structure with fine alfa-Fe grains can be obtained at an optimum velocity of the cooper roll of 20 m/s. The samples produced in these conditions had the best magnetic properties (mi0HC= 0.84 T, mi0MR = 1.05 T, mi0MS = 1.36 T, (BH)max = 160 kJ/m3) with strong exchange coupling between the hard magnetic Nd2Fe14B and soft magnetic mi-Fe phases. The amorphous phase existing between grains causes an increase in the remanence and remanence ratio.

Źródło:

Nukleonika; 2013, 58, 1; 105-108
0029-5922
1508-5791

Pojawia się w:

Nukleonika

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 44.

Tytuł:

Crystallization Processes of $R_{4.5}Fe_{77}B_{18.5}$ (R = Pr, Nd) Amorphous Alloys

Autorzy:

Musiał, A.
Śniadecki, Z.
Pagnani, D.
Idzikowski, B.

Powiązania:

https://bibliotekanauki.pl/articles/1371300.pdf

Data publikacji:

2014-07

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

61.43.Dq
65.60.+a
75.50.Bb

Opis:

The amorphous alloys $R_{4.5}Fe_{77}B_{18.5}$ (R=Pr, Nd) were prepared by melt-spinning technique under argon atmosphere on a cooper wheel rotating with surface velocity of 25 m·$s^{-1}$. The ribbons have been investigated by means of X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Temperatures of crystallization for $Pr_{4.5}Fe_{77}B_{18.5}$, measured at the heating rate 20 K/min, are equal $T_{x1}$=591°C for the first exothermic effect and $T_{x2}$=603°C for the second one (for $Nd_{4.5}Fe_{77}B_{18.5} T_{x1}$=594°C and $T_{x2}$=633°C). In the amorphous ribbons the crystallization of $Fe_{3}B$ phase in the first step, followed by the crystallization of $Pr_{2}Fe_{23}B_{3}$ and $Nd_{2}Fe_{23}B_{3}$, was observed. Both later phases appear in the process of recrystallization, immediately after $Fe_{3}B$ formation.

Źródło:

Acta Physica Polonica A; 2014, 126, 1; 316-317
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 45.

Tytuł:

Spin Reorientation Studies in Nd$\text{}_{2}$Fe$\text{}_{14-x}$Si$\text{}_{x}$B (0

Autorzy:

Gargula, R.
Pędziwiatr, A.
Bogacz, B.
Wróbel, S.
Bartolomé, J.
Stankiewicz, J.

Powiązania:

https://bibliotekanauki.pl/articles/2030427.pdf

Data publikacji:

2002-02

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

75.50.Ww
76.80.+y
64.60.-i

Opis:

Nd$\text{}_{2}$Fe$\text{}_{14-x}$Si$\text{}_{x}$B (x=0.25, 0.5, 0.75, 1.0, 1.5, 2.0) intermetallic compounds were investigated by magnetometry, $\text{}^{57}$Fe Mössbauer effect, electric resistivity, and differential scanning calorimetry mainly in the vicinity of the spin reorientation temperature, T$\text{}_{SR}$. The Curie temperature, T$\text{}_{C}$, and T$\text{}_{SR}$ were determined for different compositions and the spin phase diagram was constructed. $\text{}^{57}$Fe Mössbauer spectra showed noticeable changes in the reorientation region. For temperatures above the transition, the spectra were analysed using 6 Zeeman patterns associated with 6 inequivalent crystal sites in Nd$\text{}_{2}$Fe$\text{}_{14}$B according to site occupations (16k$\text{}_{1}$:16k$\text{}_{2}$:8j$\text{}_{1}$:8j$\text{}_{2}$:4c:4e). In the transition region, 12 subspectra had to be incorporated in the analysis. Electric resistivity measurements showed a typical metallic behaviour with no anomalies in the magnetic transition region. Differential scanning calorimetry measurements revealed broad endothermic two stage peaks around T$\text{}_{SR}$.

Źródło:

Acta Physica Polonica A; 2002, 101, 2; 289-294
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 46.

Tytuł:

Synthesis of $Fe_4[Fe(CN)_6]_3$·$14H_2O$ Nanopowder by Co-Precipitation Technique and Effect of Heat Treatment

Autorzy:

Rohilla, S.
Lal, B.
Sunder, S.
Aghamkar, P.
Kumar, S.
Aggarwal, A.

Powiązania:

https://bibliotekanauki.pl/articles/1535871.pdf

Data publikacji:

2010-10

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

81.07.-b
64.70.Nd
61.82.Rx

Opis:

Nanopowder of iron cyanide hydrate (member of Prussian blue family) was obtained using ferric chloride and potassium cyanide in their dilute solution through co-precipitation method. The effect of thermal annealing on iron cyanide hydrate nanocrystallites have been studied in detail. The formation of $Fe_4[Fe(CN)_6]_3$·$14H_2O$ and iron oxides was revealed by the Fourier transform infrared spectroscopy. The crystal structure, morphology and size of nanocrystallites were investigated by X-ray diffraction and transmission electron microscope. Results suggest that using co-precipitation technique, nanopowder of iron cyanide hydrate, in typically spherical shape, can be obtained and their thermal treatment also yield iron oxide nanocrystallites of spherical with good homogeneity. The size of the prepared nanocrystallites was found in the range 20-36 nm. It was observed that thermal treatment, typically at 800°C (4 h), iron cyanide hydrate ($Fe_4[Fe(CN)_6]_3$·$14H_2O$) nanocrystallites transformed into iron oxide ($α-Fe_2O_{3,}$ hematite) nanocrystallites.

Źródło:

Acta Physica Polonica A; 2010, 118, 4; 696-700
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 47.

Tytuł:

Magnetic properties and surface domain structure of (Nd0.85Dy0.15)10Fe83Zr1B6 thin ribbons

Autorzy:

Ceglarek, A
Plusa, D
Dospial, M
Nabialek, M
Wieczorek, P

Powiązania:

https://bibliotekanauki.pl/articles/173512.pdf

Data publikacji:

2013

Wydawca:

Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej

Tematy:

nanocomposite materials
melt spinning method
Re–Fe–B alloys
hard magnetic magnets
surface domain structure

Opis:

In this paper, the nanocrystalline (Nd0.85Dy0.15)10Fe83Zr1B6 ribbons produced by melt-spinning have been investigated by the X-ray diffraction method (XRD), vibrating sample magnetometer (VSM) and magnetic force microscopy (MFM). The XRD studies showed that material investigated was mainly composed of Re2Fe14B and α-Fe phases with fine grain sizes of 25 and 9 nm, respectively. The magnetic parameters determined from the hysteresis loop measurements are as follows: μ0HC = 0.96 T, μ0MR = 0.76 T, μ0MS = 1.09 T, (BH)max = 88 kJ/m3. The large remanence ratio (μ0MR/μ0MS) of 0.7 results from the exchange coupling between the soft and hard magnetic grains. The large surface interaction domains revealed by MFM confirmed the existence of strong exchange coupling between nanosize grains.

Źródło:

Optica Applicata; 2013, 43, 1; 117-122
0078-5466
1899-7015

Pojawia się w:

Optica Applicata

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 48.

Tytuł:

Magnetic Properties of Thin Films of Fe-Cu-R-Si-B Alloys with R = Nd, Gd, Ho, Y

Autorzy:

Gościańska, I.
Ratajczak, H.
Urbaniak, M.
Konč, M.

Powiązania:

https://bibliotekanauki.pl/articles/1953190.pdf

Data publikacji:

1997-01

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

68.55.-a
75.70.-i

Opis:

Hysteresis loops of thin films of Fe$\text{}_{73.5}$Cu$\text{}_{1}$R$\text{}_{3}$Si$\text{}_{13.5}$B$\text{}_{9}$ (R = Nd, Gd, Ho, Y) alloys were studied by the magnetooptical Faraday method. The films were deposited by flash evaporation technique onto cooled glass substrates. Lanthanides were chosen as substitutes for niobium in the FINEMET type alloys. Coercivity, H$\text{}_{c}$, was determined from the easy- and hard-axis hysteresis loops. The as-deposited films containing Gd and Ho are characterized by rather low values of H$\text{}_{c}$ while the films with Nd and Y show a high isotropic value of H$\text{}_{c}$. Attempts were made to determine the conditions of the film annealing which would ensure the optimum soft magnetic properties of the films studied.

Źródło:

Acta Physica Polonica A; 1997, 91, 1; 237-240
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 49.

Tytuł:

Synthesis and Characterization of $Fe_{80}B_{20}$ Nanoalloys Produced by Surfactant Assisted Ball Milling

Autorzy:

Fadaie, A.
Akdeniz, M.
Mekhrabov, A.

Powiązania:

https://bibliotekanauki.pl/articles/1293461.pdf

Data publikacji:

2014-02

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

75.50.Kj
75.50.Tt
75.75.Fk
64.70.Nd

Opis:

In this present study attempts have been made to synthesize $Fe_{80}B_{20}$ crystalline/amorphous nanocomposite powder by using surfactant-assisted high-energy ball milling. Comparison has been made for the differences in evolved microstructure via solidification and solid state phase transformation under equilibrium and non-equilibrium processing conditions. Structural analysis reveal that initially observed $Fe_2B$ and $Fe_3B$ intermetallic phases tend to disappear even at 1 h milling time and eventually lead to the stabilization of α-Fe nanoparticles and possible formation of amorphous phase by increasing milling time. This resultant structure governs the magnetic behaviour of the $Fe_{80}B_{20}$ nanoalloy.

Źródło:

Acta Physica Polonica A; 2014, 125, 2; 597-599
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 50.

Tytuł:

Investigation of Grain Boundary Compositions and Magnetic Properties of Hot-Worked $Nd_{18}Tb_1Fe_{66.5}Co_5Al_{1.5}B_8$ Magnets

Autorzy:

Sadullahoğlu, G.
Altuncevahir, B.
Okan Addemir, A.

Powiązania:

https://bibliotekanauki.pl/articles/1399702.pdf

Data publikacji:

2013-02

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

75.50.Ww
75.50.Vv
75.50.Bb

Opis:

Magnetic properties which are related to the compositions on the grain boundaries of the NdFeB permanent magnets were studied at different hot working temperatures applied to the cast $Nd_{18}Tb_1Fe_{66.5}Co_5Al_{1.5}B_8$ ingots. Since the addition of Al caused the formation of hard magnetic μ phase between the magnetic NdFeB crystals after the pressing 800C $H_{c}$ value increased to the highest value of 8.21 kOe. According to the SEM micrographs and EDS analysis, the increase in pressing temperature, the atomic ratios in the NdFeAl compositions approached to hard magnetic μ phase with the increase in pressing temperature and its exact composition was obtained in the sample hot deformed at 800°C. Although the secondary μ phase with a high melting temperature is detremental to the alignment of c axis of the magnetic NdFeB grains along the pressing direction, we found that the magnetic properties of the magnets improve due to the presence of this hard magnetic phase on the grain boundaries.

Źródło:

Acta Physica Polonica A; 2013, 123, 2; 233-234
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

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